Index: wp-admin/includes/update-core.php
===================================================================
--- wp-admin/includes/update-core.php	(revision 17378)
+++ wp-admin/includes/update-core.php	(working copy)
@@ -364,6 +364,9 @@
 
 	// Remove maintenance file, we're done.
 	$wp_filesystem->delete($maintenance_file);
+	
+	// allow for commit transaction
+	do_action( 'updated_core' );
 }
 
 ?>